If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

More than discoloring, I'd be worried about scratching it up as this is VERY easy to do and will 'fog' the surface.

Take a clean 1Qt spray bottle and fill it most of the way with water, then add 2 drops (less is more here!) of Dawn & slosh back & forth to mix.

The Dawn is great as a lub + will cut thru the grease & built up vinyl evap film that is no doubt present.
Spray on a clean microfiber towel, you want it fairly wet, but not running/dripping or soaked & gently clean the plastic.
Follow with another MF towel with just plain water & another to lightly dry. If there are spots that didn't come clean, you can wipe them a little harder.

Be sure to do all this when it's cool as the plastic is more likely to scratch when hot !!

If it is scratched up (very likely on an older car) you can minimize it by applying a light coat of any good spray/liquid wax.
Again use the MF to lightly apply a sparing amount, putting the product on the towel & gently wipe off immediately after it hazes.